Yb3+/Er3+ co-doped Mg-substituted tricalcium phosphate upconversion materials for bioimaging

Abstract

Yb³⁺ and Er³⁺ co-doped Mg-substituted tricalcium phosphate (Mg-TCP) upconversion particles were synthesized using a two-step process: Single-phase Mg-TCP-Yb³⁺/Er³⁺ materials with an average particle size ∼ 130.2 nm can be obtained by the hydrothermal reaction at 180 °C for 24 h, followed by heat treatment at 800 °C for 4 h, which demonstrated excellent upconversion green luminescence around the 520/550 nm wavelength. The culture of MC3T3-E1 cells with the extraction medium from Mg-TCP-8%Yb³⁺/Er³⁺@800°C materials showed obvious proliferation with increase of culture time and noncytotoxicity. Additionally, the intracellular imaging of Mg-TCP-8%Yb³⁺/Er³⁺@800°C through endocytosis by cells demonstrated that the particles can be significantly degraded within 24 h, which showed great potential for bioimaging applications.